A machine type communication (Machine Type Communication, MTC) device can communicate with a network side merely after two-way authentication between the MTC device and the network side succeeds. In the 3rd generation partnership project (3rd Generation Partnership Project, 3GPP) standard, a group-based attribute is put forward for the distribution of MTC devices, that is, the MTC devices that are located in the same geographic location, have the same attributes, or belong to the same user may be taken as a group. A group of MTC devices can directly access a network, and can also access the network through a gateway.
In the prior art, each MTC device has an international mobile subscriber identity (International Mobile Subscriber Identity, IMSI), and the identity IMSI is unique. In a process of two-way authentication between the MTC device and the network side, the network side generates an authentication vector (Authentication Vector, AV) according to a basic key K which corresponds to the unique IMSI of the MTC device, and completes the two-way authentication between the MTC device and the network side according to the AV. Different MTC devices generate different authentication vectors AVs by using different basic keys K which correspond to different IMSIs, so as to complete the two-way authentication.
Since the number of the MTC devices is large, if the existing authentication method is adopted, when a large number of MTC devices access the network in a short period of time, the signaling traffic generated during the authentication process increases rapidly, resulting in network congestion.